During various phases of oil and gas operations it becomes necessary to decontaminate liquid drawn from a wellbore. When a well is drilled, common practice is to displace the well with a completion fluid to insure the wellbore is not contaminated. However, after extended use of the completion fluids, the fluids themselves can become hydrocarbon contaminated.
Hydrocarbon contamination in brines, completion fluids, frack return water, wash-water, produced water, rig site waste pit water, and other clear fluids used in the drilling and completion processes can disrupt the continued use of the liquid. Strict laws are in place regulating the maximum allowable level of hydrocarbon contamination of these fluids. If a completion fluid has more than one percent contamination, the fluid must be either taken out of use or decontaminated.
A standard decontamination process uses cartridge filters which remove hydrocarbons from pass-through fluids. An alternative standard decontamination process uses a diatomaceous earth (DE) filter press. DE filter presses are very large and have a high operating expense. For these reasons, they cannot always be used on small oil rigs or to decontaminate inexpensive fluids. Thus, contaminated completion fluids must be shipped to a disposal or decontamination site, or diluted to a contamination level of under one percent. Such difficulties can lead to longer servicing time and increased costs.